(1) Field of the Invention
This invention relates to a new antitumor antibiotic and to its production and recovery.
(2) Description of the Prior Art
The antitumor antibiotic of the present invention, BBM-1644, is a new member of the protein antitumor antibiotics exemplified by neocarzinostatin, macromomycin and auromoycin.
Neocarzinostatin (also called zinostatin) is an acidic protein macromolecule of molecular weight 10,700 consisting of a single polypeptide chain of 109 amino acids cross-linked by two disulfide bridges. Production of neocarzinostatin by fermentation of strains of Streptomyces carzinostaticus var. neocarzinostaticus is disclosed in U.S. Pat. No. 3,334,022 and in J. Antibiotics 18: 68-76 (1965). The amino acid sequence of neocarzinostatin is disclosed in Cancer Treatment Reviews 6: 239-249 (1979).
Macromomycin is a neutral or weakly acidic polypeptide with an approximate molecular weight of about 15,000. Production of macromomycin by fermentation of Streptomyces macromomyceticus (NIHJ MC-8-42) is disclosed in U.S. Pat. No. 3,595,954 and in J. Antibiotics 21: 44-49 (1968). Purification of macromomycin and characterization data for the purified compound are disclosed in J. Antibiotics 29: 415-423 (1976).
Auromomycin is a weakly acidic polypeptide with a molecular weight of about 12,500 and an isoelectric point of pH 5.4. It consists of 16 different amino acids. Isolation of auromomycin from the culture broth of Streptomyces macromomyceticus and characterizing properties of the purified product are disclosed in J. Antibiotics 32: 330-339 (1979).
BBM-1644 may be differentiated from known polypeptide antitumor antibiotics such as neocarzinostatin, macromomycin and auromomycin by physico-chemical properties such as molecular weight, amino acid content and paper electrophoresis.